A 20-year-old primigravida was referred at the ultrasound department at 34 weeks of gestational age for an unspecified fetal mass. Her past surgical and obstetrical history were uneventful. Before and during pregnancy the patient had been using soft drugs (marijuana). The patient refused karyotyping.

There are 3 video clips of the shoulder (1.1 MB) and the chest (0.9 MB) which demonstrate the findings better then the images below. There is also a combined clip that is more complete (but adds no further findings) and is 5.8 MB

The first set of images are the shoulder of the baby (the other side presents similar findings)

The neck:

The normal brain of the baby (the image was not obtained to demonstrate the brain, thus the oblique cut, but there is no brain alterations of size or morpholgy).

The chest of the baby:

When you have tried to solve the case on your own (no team work here please !) you can find the Answer here.